The functional decline in cardiovascular and metabolic reserve which occurs with advancing age may not be solely attributed to biological aging but may derive in part from the increasingly sedentary life style that accompanies aging. To determine the role of physical activity in preserving functional capacity, we have measured body composition, maximal aerobic capacity (VO2max), cardiac volumes at rest, during maximal bicycle exercise and lower body negative pressure, blood lipids and glucose tolerance in 19 highly trained men (T) aged 60-76 years.